Blowpipe



0d;- 24, 1950 w. s. BoEDEcKl-:R ET AL 2,527,297

BLOWPIPE Filed March 15, 1946 Patented Oct. 24, 1950 UNITED simTrzfs @UFFICE N Woodrow. Boedecker andMatt.H.'Wigton, Chicago, Ill... -rassignors to The Bastian-Blessing Company, Chicago,.lll., aeorporation of Illinois Appncation'March i5, 1946,'s'eria1Nou654so This invention relates generally -to blowfpipes and more lparticularly to a cutting `tip for lflame gouging of ferrous metals.

Flame gouging is a cutting operation 'wherein a groove is cut in a ferrous metal sur-face. The operation consists of preheating a portion of lthe metal to its ignition point, 'igniting the metal with a stream of cutting oxygen and maintaining that vignition while moving the stream of oxygen over the metal surface to burn theY metal away.

Gouging is commonly used `in preparing `steel plate edges for welding. Two plates to 4be welded together are :usually laid side by Lside and a vgouging cut made vin their surfaces along vthe lin'e formed by their intersection. The groove thus formed is then filled in by welding. Y

Gouging may also be used to remove 'defective metal or cracks `from the surfaces of ingots,cast ings, or plates.

Blowpipe tips for these purposes are generally provided with a centralpassage for ldischa'rg-ii-ig a stream of oxygen, and the preheat is accomplished by fuel and oxygen mixtures arranged around the central passage.v

The velocity ofthe stream of cutting oxygen is important. If the stream .is of too high a velocity it will be uncontrollable and cut erratically rather than smoothly. However, the velocity and quantity of oxygen must be high enough to provide rapid and clean work.

In the past the velocity of the oxygen stream has been controlled by making a section fof the oxygen passage of a smaller cross section thanv Y stream of oxygen is movedrapidly enough t0 coni trol depth, the cut is lnot `wide enoughanda jrepeat cut has to -be made, thus wasting expensive gases.

This is true because theconventional tips have necked down sections of the cutting oxygen passage vand will not function properly if vthe oxygen pressure is too great, 'for the necked down ,portion will act like a nozzle fand produce a `high velocity jet which lwill pass out of the end of the tip before expanding to the cross-sectional area of the passage. This jet then will splatter the molten metal and cut erratically.

:One Vobject of this invention is'to provide a 4 claims. l(o1. 15s-T214) f ing tip.

compact gouging tip of the tip mixing type which Will provide a `.well spread stream of oxygen of substantially uniform velocity throughout its :sectional dimension.

A further object of the Vinvention is toprovide anA oxygen flow controlling device in a blowpipe tip wherein the stream of oxygen as it leaves the device is already expandedagainstthe side walls of the cutting stream tip passage with a minimum of turbulence.

A further object of this invention is to provide a flowcontrol in the oxygen passage of a gouging tip which can be easily removed and 'renewed `if fouled or replaced by one of different characteristics to control the velocity components ofv the oxygen stream in relation to the volume then desired. v

Although this invention in the broader sense is adaptable vtoa widevariety'of blowpipe arrangements, it lwill be described herein in connection with a gouging tip of the type which seats within a conical oi' tapered seat where corresponding annular kgrooves areprovided in the make-up connection for conducting the separate gases into Vthe several conduits within the tip from respec tive conduits in a torch head.

Other objects and features of novelty will be apparent from the following specification and the appended claims when read in connection with the drawing ink which one embodiment of the in' vention is illustrated by Way of example including the use of the invention in preparing abutting edges of Vmetal plate for welding. v

In the drawing: l

Fig. l is a general view showing a gouging torch in cutting position as connected ready for operation.

Fig. 2 is a sectional view of a piece of metal after a gouging cut has been made. Section is taken perpendicular to length of cut.

Fig. '3 is a cross-section of the assembled goug- Fig. 4 is lan enlarged cross-section of a portion of the tip taken on line 4-4 of Fig. 3, vshowing the ow controlling `means in thev oxygen passage. v

Fig. 5 is 'a ycross section lof a tip having a modified "type of slotted iiow controller. 'f

Fig. 6 is an enlarged cross section of the preferred type of vslotted flow controller and "insert pin. f

iin Fig. l a blowpipe 3| equipped with an embodiment of this invention 10 is shown connected by iiexible hoses '34 to oxygen and acetylene contai-iners 33. A gouging tip |10 is lattached tofthe blowpipe head 21 and the assembly is shown in the proper position relative to the work 29 for name gouging. As the cutting progresses the tip will be advanced along a predetermined or desired path across the work 29.

The gouging tip I shown in Fig. 3 is of substantially conventional form. The elongated cylindrical tip body I0 may be either straight or curved to suit the application in which it is used. However, the invention makes it possible to have a bent form of a tip without sacrificing smoothness and uniformity.

The tip body I0 is provided with an axial cen- 4 with minimum turbulence. This free and open flow eliminates possible reverberation and brings to the unit a uniformly spread stream of moving gas.

The cutting oxygen stream then passes through the unit 20 where the slots 23 separate it into several streams which are spread laterally toward the sides of the forward portion I9 of the passage. They remingle to form a lower velocity stream which is free from turbulence but the outer edges of these streams are accelerated Y. enough to overcome surface friction with the tral oxygen passageway II whose rear end I2 f corresponds with a passage in the torch head 21. The forward end of the oxygen passage II terminates in the oxygen port I3. Disposed upon opposite sides of the oxygen passage II are two sets of mixing passageways I4 which carry streams of an oxygen and combustible gas mixture and terminate in the forward end of the tip I0 in preheat ports I5. The passages I4 are bifurcated at their rear ends to provide a combustible gas or fuel inlet passage I5 and low pressure oxygen inlet passage I1. The fuel inlet passages I6 are in communication with corresponding passages in the torch head 21 and the low'pressureY oxygen inlet passages are in communication with corresponding passages in the torch head 21.

The upstream portion I8 of the oxygen passage is preferably of a uniform diameter throughout. While the diameter of the downstream portion I9 is a little larger, it is only enough larger to provide a shoulder 2| that locates a slotted flow control unit 29. The unit 20 is cylindrical in shape, having an axial bore 39 extending from one end to approximately the middle, and a plurality of circumferentially spaced slots 23 extending from the other end to a point beyond the blind end of the bore 39. A tapered axial hole 22a extends from the slotted end of the unit 20 to the blind end of the bore 39. The unit 20 is forced up against the shoulder 2| after insertion through port I3. A tapered insert pin 22 preferably streamlined to reduce possible turbulence is then forced into the hole 22a, The pin when wedged in place holds the unit l2|] in place against the forward thrust of oxygen by forcing the slotted walls 24 outwardly'against the sides of the passage I9.

The alternate form of unit 25 shown in Fig.'5 is placed in the forward oxygen passage I9 with its slotted end 26 toward the shoulder 2| rather than toward the orice but isy otherwise similar to the rst described obstruction piece 20. This moded unit is designed for use in smaller sized tips. A Y

The tip may be manufactured in any suitable manner, for example, drilling all' passageways, inserting wire mandrels to prevent closure of the passageways and swaging to desired shape.

In -assembling the tip the unit 29 or 25 is pushed into the forward oxygen passage I9 and the insert pin 22 or 28 is driven into the cavity in the center of the plug so as to spread the slots 24 or 29 and firmly hold the plug in place.

The operation of this invention is as follows: The rear end of the tip I9 is inserted into a suitable torch which is in turn connected to sources of oxygen and fuel. The torch is lighted, adjusted and brought into proximity to a work piece for preheating. A valve on the torch is then manipulated to admit the cutting oxygen into port I2. The oxygen ows freely toward the unit (SII walls of the passage so that when they reach the end of the passage the velocity of the gas sectionally speaking is uniform throughout. This stream when it emerges from the port I3 will cut a substantially semi-circular groove 39 in the ferrous metal 29 by thermoohemical reaction.

Tests of several embodiments of this invention show that much higher speeds of gouging can be obtained than has been possible with conventional gouging tips. For instance although a conventional tip will gouge at a rate of 20 to 35 inches per minute, an operator using an embodiment of this invention is able to make very smooth and uniform gouging cuts at the rate of over inches per minute without excessive splattering of molten metal and slag.

A further advantage with the present invention is its ease of operation. Conventional tips are usually quite difficult to operate and considerable practice is required before the average blowpipe operator becomes proficient in the operation of gouging. However, the operation of this invention is extremely simple and novices have become proficient in its operation in short periods of time.

The superiority of this invention is believed to be the result of the novel method of eliminating the sectional differences in velocity that existed with conventional cutting oxygen streams. The slotted flow control unit used in this invention will not form a jet or provide a jetting action experienced with conventionaltips, for even if excessive pressure is used the higher velocity portion of the stream will be the outer shell rather than the central core. This condition is quite advantageous for it does not produce erratic cutting, and consequently a much higher oxygen pressure may be used to achieve higher cutting speeds. Not only this but the slots in the unit 20 can be so arranged that more flow area can be disposed on the outside of the bend in the passage I I to increase the eifective volume of oxygen on the lower portion of the stream of cutting oxygen where the most metal has to be removed.

In some respects we are not able to account fully for the improved results which are obtained by the method and apparatus of this invention, and it should be understood that any attempt to analyze the theory which is believed to be respon,- sible for these results is to be construed not as defining a mode of operation but merely as a possible explanation of certain physical phenomena which have been observed.

Various changes or modifications in the embodiment of the illustrations or described herein may be made for special purposes of design without departing from the scope of the invention as defined by the following claims.

What is claimed is:

1. In a blowpipe, a gougingtip having a passageway therethrough for oxygen, and a flow control unit disposed4 in the oxygen passageway near the outlet thereof, said unit comprising an elon-v gated body having a passage therethrough, means forming a plurality of circumferentially spaced radial slots in said body extending longitudinally from a point proximate the middle to one end of said body and intersecting the passage, and a pin extending from saidone end of saidk passage to a depth less than the length ofthe slots whereby oxygen entering said passage is directed radially outwardly to now through the slots and in proximity to the wall of said oxygen passageway.

2. In a gouging tip having a passageway for oxygen, a flow control unit in said passageway comprising an elongated body, means defining a passage through said body, said passage having a downstream portion of a smaller diameter than the remainder of the passage, said body having a plurality of longitudinal slots therein, said slots extending a short distance beyond the upstream end of the smaller portion of said passage and to the downstream end of said body, and said slots also extending from the outer circumference of said unit inwardly into said passage, and a pin inserted into said smaller diameter portion of said -passage whereby oxygen flowing in said passage is directed into said slots.

3. In a gouging tip having a passageway for oxygen, a flow control unit in said passageway comprising an elongated body, means defining a passage through said body, said passage having an upstream portion of a smaller diameter than the remainder of the passage, said body having a plurality of longitudinal slots therein, said slots extending a, short distance beyond the downstream end of the smallerfdiameter portion of said passage and to the upstream end of the body and said slots also extending from the outer edge of said body inwardly into said passage, and a pin inserted into said smaller diameter portion of the passage, whereby oxygen iiowing from said passageway into said slots is directed into said passage.

4. In a blowpipe tip having a passageway for oxygen, a flow control unit disposed inV said passageway, said unit comprising an elongatedcylindrical body having an axial bore extending inwardly from one end to a point near the middle of said body, said body also having a plurality of longitudinal slots disposed about its circumference, said axial bore and said slots extending inwardly from opposite ends of the body, the inner ends of the slots being in communication with the bore and the slots having a depth less than the radius of the body.

WOODROW S. BOEDETCKER. MATT H. WIGTON.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 1,471,694 Jenkins Oct. 23, 1923 1,494,009 Napolitan May 13, 1924 1,912,612 Wills June 6, 1933 2,033,568 Coberly Mar. 10, 1936 2,258,456 Jones Oct. 7, 1941 2,335,330 Wigton Nov. 30, 1943 2,365,411 Jacobsson Dec. 19, 1944 2,368,716 Marra Feb. 6, 1945 2,378,346 Wigton June 12, 1945 

